Alfred guyot



. A. GUYOT.

' commuous PROCESS FOR THE PREPARATION OF MONOCHLORACETIC ACID STARTING FROM TRICHLORETHYLENE.

APPLICATION FILED-SEPT-ZII i918.

Patented Nov. 25, 1919.

14L FRED Guy 0T m WM ALFRED. GUYOT, or ssnmnans, Flt-ALICE, Assmmsr loom-Acme nns raonurrs CHIMIQUES IDALAIS El 1m LA GAM BGUE OEBABIS; Eamon, a coaroaATroN or,

FRANCE.

CONTINUOUS r'nocrss FOR, THE PREPARATION or MONOCHLOBACETICACID STARTING FROM TRICHLORETHYLENE.

To'all whom it may concemr Be it .known thatI, ALFRED of trichlorethylene is passed into hot and sufficiently diluted sulfuric acid, the water which is contained in this acid. is progresthat is to say with the, formation oftwo;

molecules of hydrochloric acidand one molecule of monochloracetic acid.

. However, it would be difficult to make fuse ofthis observation to prepare 'i'ndus trially' large quantities of chloracetic acid,

because thesmall quantity of water afforded by 'the sulfuric acid at 90% would necessitate apparatus of very large capacity,

- whereas the nature of the substances em ployed and'of the products formed in the reaction (sulfuric acid, hydrochloric acid specification of Iietters Patent.

GUYoT, a, citi zen of the Republic of France, and a resident of Salindres, Department of- 'Gard, France, have invented new and useful Improvements in Continuous Processes for the Preparation.

Patented Nov. 25, 1919.

Application filed September 21, 191s. Serial No. 255,182.

proportionately to its formation by causing an excess of trichlorethylene to bubble into .the. reactlon liquid, this excess being greater as the working temperature is lower.

Taking account of these observations, I have worked out a continuous process for the preparation of the chloracetic acid, which process can be carried out in any suitable apparatus.

The accompanying drawing represents schematically in broken vertical elevation,

an illustrative apparatus in which the process may be successfully carried out.

The boiler A, in which are arranged baffles W, is heated by an oil bath A to a temperature at whichthe trichlorethylene contained therein is evaporated. The boiler. A is connected by pipes B-C to a receptacle D containlng sulfuric acid and heated by fur- V nace E. The pipe F connects this receptacle to a reflux condenser G, the coil of which opens at one end to the bottom of a washing tower I, filled with fragmentary ma-v terial which afl'ords a large contact surface and through which constantly percolates pure trichlorethylene. The tower I is connected near its upper end to the lower portion I of a second washing tower K,

through which constantly percolates cold water; A decanter .L isconnected to the lower'end of column K. The coil of the reflux condenser G is connected at its lower end toa decanter M, from which the pipe Q, leads to the boiler A. The latter is furthermore connected with a second boiler S,

baffled at W, heated by an oil bath S and connected by pipe T to a collector U.

The vapors of trichlorethylene rising from the boiler A, pass through B--C into the sulfuric acid contained in the heated receptacle D. The vapors and gas which escape therefrom comprise essentially a mixture of hydrochloric acid, trichlorethylene, chloracetic acid and a little steam. These pass through the tube F to the reflux condenser G. The hydrochloric acid gas through H, carrying with it, although quite cold, considerable quantities of chloracetic acid and trichlorethylene. It is completely deprived of chloracetic acid by its passage through the. washing tower I, in which it contacts with the pure trichlorcthylene percolated therethrough.

escapes The dry hydrochloric acid gas, saturated with trichlorethylene from the first washing tower I, passes into the second washing tower K, through which cold water percolates. Here the hydrochloric acid is dissolved and the trichlorethylene is condensed, the latter being separated from the hydrochloric acid and completely recovered.

- ""lhe'liquid condensed in the reflux condenser G mixes with the liquid discharged from the washing tower I, and forms a mix ture of chloracetic acid, trichlorethylene and a littlewater. It passes to the decanter M where the water separates and automatically flows ott' through the pipe N. This water, which is of course heavily charged with mono-chloracetic acid, is mixed in the receptacle O with the water constantly introduced into the apparatus through pipeD to maintain constant the concentration of the sulfuric acid.

The liquid separated from the water and constituting solely a solution of chloracetic acid in trichlorethylene, returns to the boiler A by the pipe Q. The trichlorethylene is there vaporized and reenters the general circuit of the apparatus by the pipes BC, while the chloracetic acid passes into the sec ond boiler S, in which it is freed from the little trichlorethylene which it may still contain and which renters the general circuit by the pipe S The chloracetic acid flows out continually through the pipe T with the collector U, where it is recovered.

A connection V opening to the pipes B-C serves to .feed the washing tower I with trichlorethylene through the condenser X.

A supplemental feed of trichlorethylene from Y maintains constant the quantity thereof in circulation through the apparatus.

It has been recognized that the temperature, at which it is convenient to work in order to carry out the process intended, may vary within considerable limits. The formation of chloracctic acid is already determined at a temperature below 160 (J. and it still continues, without appreciable secondary reactions, above 190 C.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be per formed, I declare that what I claim is 1-- A continuous process for the preparation of monochloracetic acid by the action of trichlorethylene upon sulfuric acid of at least 90% concentration consisting in maintaining the concentration of the sulfuric acid, by the addition of water, within the limits in which it is capable of causing the reaction and in eliminating the chloracetic acid proportionately to its formation from the medium in which it is formed, by a current of vapor of trichlorethylene.

In testimony whereof I have signed my name to this specification.

ALFRED GUYOT.

Witnesses CHARLES DoNrr, M. DEFEVREMONT. 

